After my computer crashed several chunks are misplaced and/or copied from somewhere else.

What I expected to happen was...:
Reload of the map as it was before.

What actually happened was...:
Most of the map still looks the same, but some chunks are misplaced and/or replaced by chunks from somewhere else.

Steps to Reproduce:
1. Not sure, I can reproduce my laptop crash.
2. ...
3. ...